Radio products increasingly operate over a wider range of frequencies and waveforms, necessitating filters and switching paths that can accommodate wide radio frequency (RF) bands and high power signals without sacrificing performance (i.e. maintaining high rejection and low insertion loss). Many modern radios are further required to operate under harsh environments with high vibrations, extreme temperatures, and the like. Moreover, modern devices are constantly being manufactured on smaller scales, thus creating a need for more robust circuitry, such as tunable filters instead of switchable fixed filter arrangements.
Current methods of handling wide frequency ranges suffer from various disadvantages. For example, switched filter banks can be relatively large, require complex circuitry, and suffer from switching delays. Varactor-tuned filter banks are designed with varactors functioning as variable capacitive elements. These circuits tend to be more robust; however, varactors are sensitive to thermal variations, and as such, they are unable to handle high power signals without significant losses in performance. Fixed center frequency cavity filters, such as combline or evanescent mode filters, have desirable performance characteristics; however, they lack flexibility in center frequency tuning and are typically restricted to factory settings. Given the disadvantages associated with currently employed filter arrangements, there is clearly a need in the art for electronic circuitry and/or components that enable robust filter and switching path configurations without sacrificing flexibility, signal quality, or performance.